Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the description earns credit by disclosing the shape of the data: per-set reps and weight, total reps per exercise, and the planned targets being worked against. The bodyweight caveat (volume in kg always 0) is genuinely useful behavioral context. It stops short of discussing limits beyond what the schema says.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Dense but front-loaded: the core purpose comes first, then usage contexts, then the narrowing hint. Every sentence carries information, though the bodyweight aside is a slight tangent that lengthens an already packed paragraph.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description need not explain return values, yet it helpfully characterizes the payload anyway. Combined with full parameter documentation and annotations, an agent has everything needed to call it correctly; only explicit alternative-routing is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description reinforces the exercise_name use case ('compare one movement across its last few sessions') but adds no syntax or format detail beyond what the schema already documents for limit, workout_id, exercise_id, and exercise_name.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource — retrieving completed sets with reps, weight, and planned targets — and clearly distinguishes this tool from siblings like get_workout, list_workouts, and get_exercise_progression by framing it as 'what the user ACTUALLY did', set by set. An agent can identify the tool's domain without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit usage contexts ('how did I do?', progressive overload coaching, bodyweight work) and a narrowing pattern via exercise_name for comparing a movement across sessions. It lacks explicit when-not-to-use guidance or named alternatives, but the contextual routing is strong.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.